Co-pending U.S. patent application Ser. No. 356,061, Dodrill, entitled "Method of Treating Fuel for An Internal Combustion Engine to Improve Mileage" indicates that by heating fuel to an optimum temperature, the combustion efficiency of the fuel is significantly improved.
In the case of prime movers on vehicles using gasoline-powered internal combustion engines or diesel engines, the present method of preheating the fuel is to route the fuel lines close to the engine block in order to pick up radiated heat. This, however, provides no means of controlling the fuel temperature and is ineffective because of the inadequate fuel line heat transfer area and the great variations in the ultimate fuel temperature, depending upon ambient air temperature and fuel flow rate through the fuel line, in turn depending upon the speed of the vehicle.